Abstract: A single-stage melt polymerization process for the production of high molecular weight polybenzimidazole is provided. The process comprises reacting a monomeric reactant or reactants, which are capable of reacting to form a polybenzimidazole, at a temperature above the melting temperature of the monomeric reactant or reactants in the presence of a catalyst selected from the group consisting of organic sulfonic acids, halogenated acetic acids, and non-oxidizing inorganic acids. The polybenzimidazole is preferably produced by the reaction of 3,3',4,4'-tetraaminobiphenyl with isophthalic acid at a temperature within the range of approximately 360.degree. C. to 425.degree. C. for a period of time within the range of approximately 3 to 5 hours in the presence of approximately 0.25 to 0.5 percent by weight, based upon the weight of the isophthalic acid, of p-toluenesulfonic acid.

Abstract: Water-soluble condensation products which are not self-crosslinking and are prepared from polyacidic amines and compounds which are polyfunctional towards amino groups, in an aqueous medium at temperatures from 0.degree. to 120.degree. C. and pH values above 6 in the presence of emulsifiers are used in the production of paper.

Abstract: N-Hydroxyalkyltrimellitic acid imides of high purity are prepared by reacting trimellitic acid anhydride with a monoalkanolamine in an aqueous medium comprising an amount of not less than about 0.025 liter of a certain specific solvent or solvent mixture per 1 mole of the trimellitic acid anhydride and can be advantageously used for production of their polymers having a high thermal stability and a good color tone.

Abstract: Filaments of a copolyamide which is derived from at least three polyamide-forming, unbranched, saturated, randomly distributed monomer components, having an average amide group frequency of one --CONH-- to 6.4 to 7.4 --CH.sub.2 -- and in which each of said monomer components is present in an amount of 10 to 60 mol %, based on the number of moles of all said components, and the sum of the mole % amounts of all monomer components is 100, said copolyamide having a melting point of less than 155.degree. C. A method of making such filaments is also disclosed.

Abstract: Processes for the production of polyamides wherein a salt of isophthalic acid and hexamethylene diamine are polycondensed in the presence of formic acid.

Abstract: Filaments and fibers formed from a ternary fibre-forming polyamide consisting essentially of the polymeric condensation product of (1) at least 50 percent by weight of hexamethylene diammonium adipate, (2) 20-40 percent by weight of hexamethylene diammonium terephthalate and (3) 2-20 percent by weight of a third polyamide.

Abstract: The process of making a catalyst for the polymerization of 2-pyrrolidone by contacting an alkali metal pyrrolidonate, a quaternary ammonium carboxylate and carbon dioxide.

Abstract: An improved process for the continuous polymerization of .epsilon.-caprolactam in the presence of water as initiator in a vertical downward-flow tubular reactor, in which the .epsilon.-caprolactam is partially polymerized at elevated temperature in a first, mechanically agitated reaction zone and is further polymerized in further reaction zones to the desired degree of polymerization. Poly-.epsilon.-caprolactam is discharged in the form of a melt. The polymerization is carried out at a gauge pressure of from 0.2 to 0.9 bar, constant in all reaction zones. The temperature in the first reaction zone is maintained according to the relationship t.ltoreq.265+43 p .degree.C., where p is the numerical value of the gauge pressure in bars which relationship is subject to the condition that the temperature be within the range of 260.degree. to 295.degree. C.

Abstract: The invention relates to a method for the cationic polymerization of lactams either substituted or unsubstituted on the lactam ring, which contain 6-16 carbon atoms, in the presence of 0.05 - 10 mol. % based on the lactam of an anhydrous salt of Cu, Zn, B, Al, Ti, Si, V, Sb, Bi, Cr, Mo, W, Mn, Fe, Co, Ni and an inorganic or organic anion such as phosphate, pyrophosphate, phosphite, sulfate, halide, carboxylate and sulfonate in the presence of 0.05 - 5 mol. % of a protic organic or inorganic acid such as pyrophosphoric, phosphorous, hydrohalic carboxylic and sulfonic. These additives can be added to lactam below 180.degree. C and the polymerization is carried out at 150.degree. - 320.degree. C for 0.1 - 200 hr. The above-specified salts, also their mixtures, can be used. The polymerization can be carried out with mixtures containing two or more lactams.

Abstract: Copolymers of 2-pyrrolidone and C.sub.7 -C.sub.12 lactams are provided in solid form, at relatively high rates and molecular weights by polymerization in the presence of alkaline catalysts and carbon dioxide, by the inclusion of an auxiliary catalyst and a copolymerization promoter comprising certain onium salts and N-acyl lactams, respectively.